src/arch/x86/pagetable_walker.hh

   1 /*
   2  * Copyright (c) 2007 The Hewlett-Packard Development Company
   3  * All rights reserved.
   4  *
   5  * The license below extends only to copyright in the software and shall
   6  * not be construed as granting a license to any other intellectual
   7  * property including but not limited to intellectual property relating
   8  * to a hardware implementation of the functionality of the software
   9  * licensed hereunder.  You may use the software subject to the license
  10  * terms below provided that you ensure that this notice is replicated
  11  * unmodified and in its entirety in all distributions of the software,
  12  * modified or unmodified, in source code or in binary form.
  13  *
  14  * Redistribution and use in source and binary forms, with or without
  15  * modification, are permitted provided that the following conditions are
  16  * met: redistributions of source code must retain the above copyright
  17  * notice, this list of conditions and the following disclaimer;
  18  * redistributions in binary form must reproduce the above copyright
  19  * notice, this list of conditions and the following disclaimer in the
  20  * documentation and/or other materials provided with the distribution;
  21  * neither the name of the copyright holders nor the names of its
  22  * contributors may be used to endorse or promote products derived from
  23  * this software without specific prior written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  26  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  27  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  28  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  29  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  30  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  31  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  32  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  35  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  *
  37  * Authors: Gabe Black
  38  */
  39
  40 #ifndef __ARCH_X86_PAGE_TABLE_WALKER_HH__
  41 #define __ARCH_X86_PAGE_TABLE_WALKER_HH__
  42
  43 #include <vector>
  44
  45 #include "arch/x86/pagetable.hh"
  46 #include "arch/x86/tlb.hh"
  47 #include "base/types.hh"
  48 #include "mem/packet.hh"
  49 #include "params/X86PagetableWalker.hh"
  50 #include "sim/clocked_object.hh"
  51 #include "sim/faults.hh"
  52 #include "sim/system.hh"
  53
  54 class ThreadContext;
  55
  56 namespace X86ISA
  57 {
  58     class Walker : public ClockedObject
  59     {
  60       protected:
  61         // Port for accessing memory
  62         class WalkerPort : public MasterPort
  63         {
  64           public:
  65             WalkerPort(const std::string &_name, Walker * _walker) :
  66                   MasterPort(_name, _walker), walker(_walker)
  67             {}
  68
  69           protected:
  70             Walker *walker;
  71
  72             bool recvTimingResp(PacketPtr pkt);
  73             void recvReqRetry();
  74         };
  75
  76         friend class WalkerPort;
  77         WalkerPort port;
  78
  79         // State to track each walk of the page table
  80         class WalkerState
  81         {
  82           friend class Walker;
  83           private:
  84             enum State {
  85                 Ready,
  86                 Waiting,
  87                 // Long mode
  88                 LongPML4, LongPDP, LongPD, LongPTE,
  89                 // PAE legacy mode
  90                 PAEPDP, PAEPD, PAEPTE,
  91                 // Non PAE legacy mode with and without PSE
  92                 PSEPD, PD, PTE
  93             };
  94
  95           protected:
  96             Walker *walker;
  97             ThreadContext *tc;
  98             RequestPtr req;
  99             State state;
 100             State nextState;
 101             int dataSize;
 102             bool enableNX;
 103             unsigned inflight;
 104             TlbEntry entry;
 105             PacketPtr read;
 106             std::vector<PacketPtr> writes;
 107             Fault timingFault;
 108             TLB::Translation * translation;
 109             BaseTLB::Mode mode;
 110             bool functional;
 111             bool timing;
 112             bool retrying;
 113             bool started;
 114             bool squashed;
 115           public:
 116             WalkerState(Walker * _walker, BaseTLB::Translation *_translation,
 117                         const RequestPtr &_req, bool _isFunctional = false) :
 118                 walker(_walker), req(_req), state(Ready),
 119                 nextState(Ready), inflight(0),
 120                 translation(_translation),
 121                 functional(_isFunctional), timing(false),
 122                 retrying(false), started(false), squashed(false)
 123             {
 124             }
 125             void initState(ThreadContext * _tc, BaseTLB::Mode _mode,
 126                            bool _isTiming = false);
 127             Fault startWalk();
 128             Fault startFunctional(Addr &addr, unsigned &logBytes);
 129             bool recvPacket(PacketPtr pkt);
 130             unsigned numInflight() const;
 131             bool isRetrying();
 132             bool wasStarted();
 133             bool isTiming();
 134             void retry();
 135             void squash();
 136             std::string name() const {return walker->name();}
 137
 138           private:
 139             void setupWalk(Addr vaddr);
 140             Fault stepWalk(PacketPtr &write);
 141             void sendPackets();
 142             void endWalk();
 143             Fault pageFault(bool present);
 144         };
 145
 146         friend class WalkerState;
 147         // State for timing and atomic accesses (need multiple per walker in
 148         // the case of multiple outstanding requests in timing mode)
 149         std::list<WalkerState *> currStates;
 150         // State for functional accesses (only need one of these per walker)
 151         WalkerState funcState;
 152
 153         struct WalkerSenderState : public Packet::SenderState
 154         {
 155             WalkerState * senderWalk;
 156             WalkerSenderState(WalkerState * _senderWalk) :
 157                 senderWalk(_senderWalk) {}
 158         };
 159
 160       public:
 161         // Kick off the state machine.
 162         Fault start(ThreadContext * _tc, BaseTLB::Translation *translation,
 163                 const RequestPtr &req, BaseTLB::Mode mode);
 164         Fault startFunctional(ThreadContext * _tc, Addr &addr,
 165                 unsigned &logBytes, BaseTLB::Mode mode);
 166         Port &getPort(const std::string &if_name,
 167                       PortID idx=InvalidPortID) override;
 168
 169       protected:
 170         // The TLB we're supposed to load.
 171         TLB * tlb;
 172         System * sys;
 173         MasterID masterId;
 174
 175         // The number of outstanding walks that can be squashed per cycle.
 176         unsigned numSquashable;
 177
 178         // Wrapper for checking for squashes before starting a translation.
 179         void startWalkWrapper();
 180
 181         /**
 182          * Event used to call startWalkWrapper.
 183          **/
 184         EventFunctionWrapper startWalkWrapperEvent;
 185
 186         // Functions for dealing with packets.
 187         bool recvTimingResp(PacketPtr pkt);
 188         void recvReqRetry();
 189         bool sendTiming(WalkerState * sendingState, PacketPtr pkt);
 190
 191       public:
 192
 193         void setTLB(TLB * _tlb)
 194         {
 195             tlb = _tlb;
 196         }
 197
 198         typedef X86PagetableWalkerParams Params;
 199
 200         const Params *
 201         params() const
 202         {
 203             return static_cast<const Params *>(_params);
 204         }
 205
 206         Walker(const Params *params) :
 207             ClockedObject(params), port(name() + ".port", this),
 208             funcState(this, NULL, NULL, true), tlb(NULL), sys(params->system),
 209             masterId(sys->getMasterId(this)),
 210             numSquashable(params->num_squash_per_cycle),
 211             startWalkWrapperEvent([this]{ startWalkWrapper(); }, name())
 212         {
 213         }
 214     };
 215 }
 216 #endif // __ARCH_X86_PAGE_TABLE_WALKER_HH__